Techniques enabling efficient transfer of a substance of interest across a biological barrier are of considerable interest in the fields of biotechnology and medicine. For example, such techniques may be used for the transport of a variety of different substances across a biological barrier regulated by tight junctions (i.e., the mucosal epithelia, which include the intestinal and respiratory epithelia, and the vascular endothelia, which include the blood-brain barrier, nasal membrane, cornea and other eye membranes, and genito-urinary membranes). In particular there is great interest in oral delivery of therapeutic agents to avoid the use of more invasive means of administration and hence improve patient convenience and compliance.
Diverse drug delivery vehicles have been employed, among them liposomes, lipidic or polymeric nanoparticles, and microemulsions. These have improved the oral bioavailability of certain drugs, mostly by the protective effect they offer. However, for most relevant drugs, bioavailability remains very low and fails to achieve the minimal therapeutic goals.
Hence, a need exists for an efficient, specific, non-invasive, low-risk means to target various biological barriers for the non invasive delivery of various therapeutic agents such as peptides and polypeptides, macromolecule drugs and other therapeutic agents which include small molecules with low bioavailability.